Anheuser-Busch said it finished its ethics inquiry.

Anheuser-Busch’s investigation centered on alleged kickbacks to certain employees from an advertising agency. In a letter to shareholders, Chairman August A. Busch III said the investigation, which began Dec. 11, has been completed, adding that the company will issue additional guidelines on corporate ethical practices soon. Four employees, including Vice President Dennis T. Long, have resigned or been fired in connection with the allegations.